Effect of surfactant addition on the morphology and pervaporation performance of asymmetric polysulfone membranes

In the present work, the separation of aqueous alcohol solution through wet -phase inversion prepared polysulfone (PSf) membrane was investigated by us ing the pervaporation process. The role played by surfactant (Span-80) in t he formation of PSf membrane was also studied. Addition of surfactant in th e casting solution can suppress macrovoids in polymeric membrane. The forma tion of asymmetric PSf membranes was discussed in terms of the presence of surfactant in the casting solution and the PSf concentration. The surface p roperties of the asymmetric PSf membranes were characterized by scanning el ectron microscopy (SEM). The effects of polymer concentration, surfactant c ontent, feed composition, and feed solution temperature on the pervaporatio n performance were investigated. The separation factor towards water and th e permeation rate for a 10 wt.% aqueous ethanol solution through the asymme tric PSf membrane with a 15 wt.% Span-80 were 16 and 240 g/m(2) h, respecti vely. (C) 2000 Elsevier Science B.V. All rights reserved.